High or low pressure signal-alarm.



No. 755,708. 1 v PATENTED MAR. 29, 1904. F. H. SCHMITZ.

HIGH OR LOW PRESSURE SIGNAL ALARM.

APPLIOATIONIILED SEPT. 4. 1903. N0 MODEL.

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UNITED STATES Patented March 29, 1904.

1 PATENT OFFICE.

FRANK H. SCHMITZ, OF NEW YORK, N. Y.

SPECIFICATION forming part of Letters Patent No. I755,708, dated March29, 1904,

Application filed September 4:, 1903. Serial No. 172,013. (No model.)

T all whom t may concern:

Be it known that I, FRANK HENRY SCHMITZ, a citizen of the United States,and a resident of the city of New York, borough of Brooklyn, county ofKings, State of New York, have invented a certain new and Improved Highor Low Pressure Signal-Alarm, of which the following is a full and exactdescription.

, The object of the invention is to provide a method of indicating whenthe pressure of steam is greater or lower than required.

My invention can be applied to an ammonia apparatus such as is used incold-storage plants, breweries, and the like and can also be used on anymachine where a certain pressure is required, either liquid or gas.

The device consists of a cylinder containing a piston-which can beapplied directly to the boiler or any pressure-pipe by means of a tube,said cylinder having a projecting pistonrod held in position by a spiralspring, so that When the pressure gets beyond the required Y or safetylimit the pressure of the steam in the piston will push the plungerhaving the piston-rod against an electrical connection, closing thecircuit and ringing an ordinary electrical bell. When there is vacuumand the water or pressure is too low in the boiler or other receptacle,the vacuum will draw back the rod against another wire and again closethe circuit.

The invention consists of novel features andy shows especially the sidearm in'normal posi-v tion, and in dotted lines the circuit is shownduring a vacuum. Fig. 3 is an elevation of the contact-block as shown inFig. 2, and Fig. 4 is an end view of Fig. l.

In the accompanying drawings, A shows the cylinder-cover partly brokenaway, so as to show the plunger B, to the upper or outer end of which isattached the piston-rod O.

D shows a pipe leading into the boiler or other receptacle on which thecylinder is secured by a thread cut on the end of said pipe. Thecylinder is also secured to a piece of wood or any other material by twobands E, passing around it and having holes in their ends through whichpass screws F. Permanently fastened to both ends of the cylinder areblocks or arms G, having openings through which the arms H can freelypass. rIhese rods H at their farther or outer end are rigidly connectedto a cross-arm I, thus forming a rectangular adjustable sliding frame onthe outside of the cylinder. Through a hole in the center of thecross-arm I passes the projecting piston-rod O. At the lower ends of therods H are screw-nuts J, which are used for the purpose of adjusting thetension of the spiral springs K and L to the amount of pressurerequired, as will be more fully described hereinafter. On the projectingpiston-rod O and between the head of the piston and the arm I, which isrigidly secured to the side bars H, are two helical wire springs K andL, separated by a nut M, which may be tightened or loosened, asrequired. The spring K is intended to give the piston-rod O a backwardmovement when there is a vacuum or a lower pressure in the boiler, andthe spring L gives it a forward movement kwhen there is a high pressure.The piston-rod C has an arm N, which is used to close the electricalcircuit when there is a vacuum in the boiler, as hereinafter` At O isshown an ordinary electric bell, with the battery'at U, having two poleswith contact-points P Q and R and V. These contact-points and theirconstruction is shown fully and in detail in Fig. 3 of the drawings. Asshown in' Fig. 3, when the piston rises or is pushed forward by anexcess of steam over the required amount in the boiler the pistonrod Cpushes the contacts V and R together and the circuit is closed. Whenthere is a vacuum and the piston descends, the arm N of the rod Opresses against the Contact Q, and the IOO contacts Q and R are thusbrought together and the circuit is closed. These contacts are made oflight spring metal, so that when the pressure of the rod is removed fromthem they spring automatically back into their normal places. rlhecontacts l) and Q are of course both on the same side of the arm N, asshown by Fig. -that is to say, between the arm N and the adjustableframe.

On the cylinder A is cut or placed a scale or indicator S, on which maybe indicated by figures the required number of pounds of pressure-forinstance, five, ten, fifteen, twenty, cm-and on one of the arms H is apointer T.

The Inode of operation of the device is as follows: Assuming' the boileris required to carry one hundred and fifteen pounds of steam and no moreor no less, the indicator T is placed opposite the ligure 115. Theindicator can be adjusted to any ligure of pressure required by turningthe screw-nuts J on the rods H, which press the springs K andL to theamount of pressure required. The steam of course passes directly fromthe boiler into the piston A, and when there is more than one hundredand fifteen pounds it forces the rod C against the contact-point of theelectrical apparatus, thus closing the circuit and ringing the bell.Should there be a vacuum or the water be too low in the boiler, thevacuum, with the aid of the spring L, will cause a back motion of thepiston-rod C, and the arm N of the piston-rod C will be forced or drawnbackward toward the cylinder and come in contact with the contact-pointP, thus closing the circuit and ringing the bell.

One of the advantages of my invention is that the device is automaticand needs no watching', and the person in charge of the engine may be inanother room or other part of the building, yet will be able to hear thealarm sound when the pressure is too high or too low. The ends of thepiston-rod and side arm are provided with insulating-caps to prevent anyundesirable electrical contact.

Having described my invention, what I claim, and desire to secure byLetters Patent, 1s-

l. In combination, an automatic high or low pressure signal-alarm,consisting of a cylinder containing a piston carrying a rod orcircuitbrealer, having an arm attached thereto and passing through arectangular adjustable sliding frame, two spiral springs on said rod orcircuit-breaker between the outer end of the adjustable sliding' frameand the head of the cylinder, separated by an adjustable nut on the rodor circuitbreaker, for the purpose of holding the piston-rod orcircuit-breaker in a stationary position; nuts on the ends of the armsor sides of the sliding adjustable frame for the purpose of regulatingthe amount of pressure required, an indicator or scale on said cylinder,on one of the arms of said frame a pointer to indicate the pressure, anelectrical apparatus, as shown and described.

2. In combination, an autoinatichigh orlow pressure signal-alarmconsisting of a cylinder containing a piston with a rod orcircuitbreaker on said piston, a rectangular adjustable sliding frame onthe outside of said cylinder, two spiral springs on said piston-rod orcircuit-breaker between the end of the cylinder and the farther end ofthe adjustable sliding frame, an adjustable nut on said pistonrodbetween the two spiral springs, nuts on the arms or lower ends of theadjustable sliding frame for the purpose of adjusting the requiredpressure, a scale orindicator, a pointer on one of the arins of saidframe, and an electrical apparatus for ringing a bell, substantially asshown and described.

3. In combination, an automatic high orlow pressure signal-alarm,consisting' of a pipe leading from a boiler or other receptacle to acylinder containing a piston, a rod or circuitbreaker attached to theplunger on said piston, a rectangular adjustable sliding 'frame on theoutside of said cylinder, two spiral springs on the piston-rod orciicuit-ln'ealr between the end of the cylinder and the farther end ofthe adjustable sliding frame, an adjustable nut on said piston-rodbetween the two spiral springs, nuts on the arms or lower ends of theadjustable sliding frame, for the purpose of adjusting the device to therequired pressure, a scale or indicator, a pointer on one of the arms ofsaid frame, an electrical apparatus for ringing a bell, substantially asshown and described.

In testimony whereof lhave signed my name to this specification, in thepresence of two subscribing witnesses, this 3d day of September, 1903.

FRANK H. SCHMITZ.'

Witnesses:

WM. E. VARLAND, (J1-IAS. A. VVILLIAMs.

